In the mid-1960's, Dr. Jonas's theories were first put into practice. A local newspaper, The Voice of Nitra, began to inform the public about the existence of the Natural Conception Control and invited volunteer couples to participate and help the research by trying the Dr. Eugen Jonas Method. By 1965, a sufficient number of volunteers became available, and Dr. Jonas's calendars were published with instructions provided in Czech, Slovak and Hungarian languages.

Clinical Tests

The infertile day tests were first performed with the help of married couples who wanted to have children, but were willing to test for the infertile days. Within six months sufficient material became available and within a year the research was complete. The results were truly satisfying, with a 97.8% accuracy. Those same couples then received a new calendar for the following year where the fertile days as well as the gender were marked, so that the couples could choose the gender of their child.

Dr. Jonas was invited to prove his theories at the Bratislava Clinic of Gynaecology, by Dr. Aurel Hudcovic. Here, he worked out individual calendars for 8,000 women who wanted to have only male babies. Ninety-nine percent (99%) of them fulfilled their dream some nine months later!
Then new trials were started with couples who produce only non-viable foetuses. Using the method, the couples chose a date for the conception of a viable child. The results were excellent: 98% reliability was again achieved.

Finally, the turn came for women who could not become pregnant at all. For them, a calculation was made for optimal days of conception for one year in advance. In this case, no consideration had been made for the gender of the child, as the conception itself was most important.

New series of tests began in July 1969 and by July 1970, applications from another 30,000 married couples from Czechoslovakia only were processed. A commission from Budapest evaluated the results and the success rate was again 98%. Dr. Jonas then travelled abroad explaining to gynaecologists, physicists and doctors the efficacy of his theories. He has also presented his calculations, tables, case histories and the results of his thesis to both the Hungarian and Czechoslovak Academy of Sciences.

A committee of gynaecologists then queried Dr. Jonas, if his technique could be worked backwards. They challenged him to predict the sex of the child, by telling him the approximate date of the impregnation. Once again, Dr. Jonas stood up to the occasion and achieved 87% accuracy off the top of his head!

The research confirmed and proved that:

Dr. Eugen Jonas Method® is 98% accurate.

Baby's sex determination is 98% predictable.

85% of the pregnancies occurred on Dr. Jonas's calculated date.

In the primary or secondary infertile applicants, 2/3 became pregnant within the first year of using this method, 1/3 within the second year.

Dr. E. Jonas's dream was to make the secrets of his painstaking discoveries available to each and every parent. With his hard work and research, his dream has come true.